Document FR-2,872,566 discloses a combustion method that notably allows to carry out total liquefaction of the carbon dioxide captured at ambient temperature. Total CO2 liquefaction requires limitation of the proportion of inert compounds present in the CO2 produced. In this method, the maximum CO2 capture ratio essentially depends on the proportion of inert gases present in the combustion fumes. In order to best limit the amount of inert gas in the fumes so as not to penalize the CO2 capture efficiency, this method must preferably work with a combustion chamber that is constantly maintained under slight overpressure in relation to the outside. It also preferably works with an oxygen production unit that can provide more than 98% pure oxygen.
The present invention provides an oxycombustion method with CO2 capture wherein the proportion of inert compounds in the CO2 is not restricting. According to the invention, it is not necessary to totally liquefy the CO2 prior to its transportation: CO2 transportation is performed after multiphase compression that allows to treat the CO2 stream comprising a significant part of the inert compounds.